In order to limit heat transfer through houses, it has become necessary and desirable to provide insulating material between attic floor joists and to considerable distances above the attic floor joists of such houses. Should this insulating material become sealed against the underside of the roofing boards between the roof rafters, however, it will cut off or severely restrict the necessary free flow of ventilating air to and from the areas in the attic above the insulating materials. Such restriction permits moisture buildup in and under the insulating material causing loss of insulation qualities and other damage, due, for example, to condensation within the walls of the house. Therefore, it is presently required to provide a free air passageway between each pair of adjacent roof rafters and adjacent the roof boards. Typically this passageway should extend from rafter to rafter and should be at least one inch deep.
This invention deals with a simple house roof insulation vent which can easily be installed to insure that this ventilating passageway is established and will be maintained during the entire life of the house while, at the same time, allowing insulating materials to be initially distributed to the maximum possible allowable depth adjacent the outer edges of the attic floor joists and on top of the outer wall plates.
An additional problem, before the present invention, was the blow by or overflow of particulate insulating material over the outer wall stud contacting wall plates at the ends of the joist runs when such insulation is being installed by blowing or by pouring. This problem as well as the problem of insuring that air space for the required ventilation flow is provided was addressed in the patent to Lind, U.S. Pat. No. 3,240,144, granted in March of 1966. In this structure, however, a simple vertical baffle plate 9 was fastened to one of the faces of the wall plate so that insulation would be blocked by the baffle plate and would not run over it along the top of the outer wall and into the soffit where it would tend to block air vents and to destroy the passageway for air to and from the soffit and the upper part of the attic. A similar structure is indicated in the patent to Bottom, U.S. Pat. No. 2,969,726, granted in January of 1961. Neither of these structures, however, provided a positive barrier to prevent reduction of the cross sectional area of the ventilating air passageway to less than a predetermined desirable minimum.
Various other plans for forming troughs of roof clearing sheets and flanges have been devised previous to the present invention, and some of them have even provided downwardly extending sheets designed to come into contact, or at least to closely approach, the upper outer vertical wall stud contacting wall plates. These structures have been deficient in that they did not provide for a positive positioning or fastening of an outer wall sheathing contact sheet, did not provide a vertical stiffener tab at the upper end of a roof clearing sheet, and did not provide for the permanent positioning or fastening of this upper end stiffener tab.
No search was made of the structure of the invention; but applicant knows of no structure which anticipates the claims presented in the specification.